pa.md (negdf2, negsf2): Use multiplication rather than subtraction to implement float...

	* pa.md (negdf2, negsf2): Use multiplication rather than subtraction
	to implement floating negation on processors prior to PA 2.0.

From-SVN: r46847

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a03ff2c63eda85712a9d252c8481c4984ebf40a5..5674392b2cae11c12e7e81a490e73a1995d3e739 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2001-11-08  John David Anglin  <dave@hiauly1.hia.nrc.ca>
+
+       * pa.md (negdf2, negsf2): Use multiplication rather than subtraction
+       to implement floating negation on processors prior to PA 2.0.
+
 2001-11-08  Jakub Jelinek  <jakub@redhat.com>
 
        * dwarf2asm.c (mark_indirect_pool_entry, mark_indirect_pool): New.

diff --git a/gcc/config/pa/pa.md b/gcc/config/pa/pa.md
index 95620693496abaac2f83f58cc4e5a78263b811f5..626d92acae56792a98c55afb7d68d3a4ffb611b1 100644 (file)
--- a/gcc/config/pa/pa.md
+++ b/gcc/config/pa/pa.md
@@ -4640,10 +4640,29 @@
   [(set_attr "type" "fpdivsgl")
    (set_attr "length" "4")])
 
-(define_insn "negdf2"
+;; Processors prior to PA 2.0 don't have a fneg instruction.  Fast
+;; negation can be done by subtracting from plus zero.  However, this
+;; violates the IEEE standard when negating plus and minus zero.
+(define_expand "negdf2"
+  [(parallel [(set (match_operand:DF 0 "register_operand" "")
+                  (neg:DF (match_operand:DF 1 "register_operand" "")))
+             (use (match_dup 2))])]
+  "! TARGET_SOFT_FLOAT"
+{
+  if (TARGET_PA_20 || flag_unsafe_math_optimizations)
+    emit_insn (gen_negdf2_fast (operands[0], operands[1]));
+  else
+    {
+      operands[2] = force_reg (DFmode, immed_real_const_1 (dconstm1, DFmode));
+      emit_insn (gen_muldf3 (operands[0], operands[1], operands[2]));
+    }
+  DONE;
+})
+
+(define_insn "negdf2_fast"
   [(set (match_operand:DF 0 "register_operand" "=f")
        (neg:DF (match_operand:DF 1 "register_operand" "f")))]
-  "! TARGET_SOFT_FLOAT"
+  "! TARGET_SOFT_FLOAT && (TARGET_PA_20 || flag_unsafe_math_optimizations)"
   "*
 {
   if (TARGET_PA_20)
@@ -4654,10 +4673,26 @@
   [(set_attr "type" "fpalu")
    (set_attr "length" "4")])
 
-(define_insn "negsf2"
+(define_expand "negsf2"
+  [(parallel [(set (match_operand:SF 0 "register_operand" "")
+                  (neg:SF (match_operand:SF 1 "register_operand" "")))
+             (use (match_dup 2))])]
+  "! TARGET_SOFT_FLOAT"
+{
+  if (TARGET_PA_20 || flag_unsafe_math_optimizations)
+    emit_insn (gen_negsf2_fast (operands[0], operands[1]));
+  else
+    {
+      operands[2] = force_reg (SFmode, immed_real_const_1 (dconstm1, SFmode));
+      emit_insn (gen_mulsf3 (operands[0], operands[1], operands[2]));
+    }
+  DONE;
+})
+
+(define_insn "negsf2_fast"
   [(set (match_operand:SF 0 "register_operand" "=f")
        (neg:SF (match_operand:SF 1 "register_operand" "f")))]
-  "! TARGET_SOFT_FLOAT"
+  "! TARGET_SOFT_FLOAT && (TARGET_PA_20 || flag_unsafe_math_optimizations)"
   "*
 {
   if (TARGET_PA_20)